The present invention relates generally to a processing apparatus and method, and more particularly to a processing apparatus and method that transfer a pattern of a mold as an original onto a substrate such as a wafer. The present invention is particularly suitable for a processing apparatus that uses the nanoimprint technology for fine processing to manufacture semiconductor devices, micro electro-mechanical systems (“MEMS's”), and the like.
The nanoimprint technology has already been known as an alternative to the photolithography that uses the ultraviolet (“UV”) light, X-rays and electron beams to form fine patterns for semiconductor devices. The nanoimprint is a technology that presses or stamps a model or a mold, on which a fine pattern has been formed by the electron-beam exposure etc., against a substrate such as a wafer to which a resinous material (resist) is applied, thereby transferring the pattern onto the resist. The nanoimprint has some types, and one method is a photo-curing method. See, for example, M. Colburn et al., “Step and Flash Imprint Lithography: A New Approach to High-Resolution Patterning”, Proceedings of the SPIE's 24th International Symposium on Microlithography: Emerging Lithographic Technologies III, Santa Clara, Calif., Vol. 3676, Part One, pp. 379-389, March 1999. The photo-curing method is a method of exposing the UV curable resin or the resist while pressing a transparent mold with the resist, and of releasing the mold after the resin is cured.
FIG. 14 is a sectional view showing a relationship among a conventional mold M, a mold chuck 11, and a mold chuck stage 12. The mold M having a relief pattern P on its surface is fixed onto the mold chuck 11 by a mechanical means (or positioning pins) 11P. The mold chuck 11 is similarly fixed onto the mold chuck stage 12 by a mechanical means (not shown). The mold chuck 11 and the mold chuck stage 12 have openings 11H and 12H for transmitting to the mold M the UV light irradiated from a light source (not shown). Plural load sensors (not shown) that serve as a force detecting means are attached to the mold chuck 11 or the mold chuck stage 12.
The mold M is pressed against the resist (not shown) via the mold chuck stage 12 and the mold chuck 11. In pressing, the mold chuck stage 12 varies the inclination of the mold chuck 11, and a servomotor (not shown) adjusts the compression state of the mold M, in accordance with the outputs of the load sensors. Thereafter, the UV light is irradiated onto the mold M via the openings 11H and 12H.
As shown in FIG. 14, the conventional mold chuck 11 applies a compression force to the periphery of the mold M, and has the central opening 11H to transmit the irradiated UV light. Therefore, in pressing, the rear surface of the mold M deforms at part corresponding to the opening 11H, and the transfer accuracy of the pattern on the mold M's surface deteriorates. As the mold M becomes large for the increased throughput of the apparatus, the opening 11H in the mold chuck 11 becomes accordingly large and the problem becomes conspicuous. In addition, the load sensors are not enough to precisely measure the compression state of the mold against the resist and the pattern transfer accuracy cannot improve consequently. Moreover, when there is a temperature difference between the mold and the wafer, the compression of the mold causes a local thermal strain on the wafer, and lowers the transfer accuracy.